I agree with mags242001. And want to add that mucus plugs looks different than discharge. Usually it come out in chunks, looks and jiggles like jello (made with weak tea) and may have brown flecks in it.
No. It's just mild bleeding caused by having sex. Nothing to worry abt. Pregnancy caused added blood flow to ur cervix n some woman bleed after it because it's so sensitive. Happens to me all the time after sex. Dr said not to worry. It's brown cuz it's old blood. Now if u start having cramps or passing clots go to the hospital or ur dr